1. Field of the Invention
The present invention relates to back door structures for motor vehicles. More specifically, the present invention pertains to back door structures for vehicle bodies having rear window portions and rear trunk portions.
2. Description of the Prior Art
There are many types of motor vehicles which have rear body portions formed with rear door openings or trunk openings adapted to be closed by back doors or trunk lids. A typical example of such back door or trunk lid is disclosed by the Japanese Utility Model Application No. 56-28604 filed on Mar. 3, 1981 and disclosed for public inspection on Sept. 8, 1982 under the disclose No. 57-143368. In the structure disclosed by that utility model application, a trunk lid is provided rearward of a fixed rear window so that packages can be thrown into and taken out of the trunk room while the trunk lid is opened. Such conventional trunk structures are, however, inconvenient for use because the door openings are not sufficiently large for accommodations of large packages. In so-called hatch-back type vehicles, wide back door openings are provided. However, this type of vehicles is also inconvenient in that back doors of a relatively large size have to be opened even where packages are small.
Japanese Utility Model Publication No. 57-5212 published on Feb. 1, 1982 discloses a hatch-back type vehicle having an auxiliary door of a small size attached to the back door. According to the proposal in that utility model application, an auxiliary door opening is formed in the rear end portion of the back door and the auxiliary door is hinged to the back door to close the auxiliary door opening. It should however be noted that the auxiliary door opening in the proposed door structure is too small even for a small package so that it cannot improve the utility of the back door structure. Further, the proposed structure is inconvenient in that the back door and the auxiliary door have to be handled separately so that when the back door is opened with the auxiliary door open, the both doors must be closed separately.